Idera Pharmaceuticals Presents Preclinical Data from its Autoimmune Disease Program at the 74th Annual Scientific Meeting of the American College of Rheumatology

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Nov 9, 2010 - Idera
Pharmaceuticals, Inc. (Nasdaq: IDRA) today announced two
presentations of preclinical data from its autoimmune and
inflammatory disease program at the 74th Annual
Scientific Meeting of the American College of Rheumatology (ACR) in
Atlanta, Georgia. One presentation is entitled “IMO-3100, a
Toll-like Receptor (TLR) Antagonist, Suppresses TLR7- and
TLR9-mediated Immune Responses in Non-human Primates” (#856).
IMO-3100 is an antagonist of TLR7 and TLR9 and Idera's lead drug
candidate being developed for the treatment of autoimmune and
inflammatory diseases. The other presentation is entitled
“Peripheral Blood Mononuclear Cells and Plasmacytoid
Dendritic Cells from Healthy Human Females Exhibit Altered
TLR7-Mediated Immune Responses Compared to Males” (#862).
Both presentations are begin given by Idera scientists.

“In the study of IMO-3100, once-weekly doses of IMO-3100
in non-human primates led to sustained suppression of TLR7- and
TLR9-mediated immune responses over four weeks of treatment, which
confirmed the intended mechanism of action of IMO-3100 with
multiple dosing,” commented Tim Sullivan, Ph.D., Vice
President, Development Programs and Alliance Management of Idera
Pharmaceuticals. “We recently completed a multiple-dose
clinical trial of IMO-3100 in healthy subjects and intend to
analyze the data by the end of the year and present the results at
a scientific meeting in the first half of 2011.”

In one of the preclinical studies presented today, IMO-3100
suppressed immune responses mediated through TLR7 and TLR9,
reducing the production of cytokines such as TNF- Î±,
IL-6, IP-10 and IFN-Î± in cells isolated from blood
samples. TLR7- and TLR9-mediated immune responses remained
suppressed by weekly IMO-3100 administration throughout the
four-week treatment period. The secretion of cytokines began to
rebound to pre-dose levels two weeks after the last dose of
IMO-3100. Importantly, IMO-3100 did not affect TLR4-mediated
responses, confirming its specific activity as an antagonist of
TLR7 and TLR9.

The other preclinical study evaluated the differences between
female and male healthy human subjects in the TLR-mediated immune
responses of isolated blood cells. The data demonstrate that blood
cells from healthy females produce higher levels of
pro-inflammatory cytokines in response to TLR7 stimulation than do
blood cells from healthy male subjects.

IMO-3100, an antagonist of TLR7 and TLR9, is a lead drug
candidate in development to treat autoimmune and inflammatory
diseases. Independent research studies suggest that
pro-inflammatory cytokines characteristic of autoimmune disease are
induced through activation of TLR7 and TLR9. IMO-3100 is designed
to block production of multiple pro-inflammatory cytokines induced
through TLR7 and TLR9. In contrast, many current autoimmune disease
treatments aim to block the activity of individual cytokines.
IMO-3100 has demonstrated potent activity in reducing pathologic
and immunologic manifestations in preclinical mouse models of
diseases such as lupus, rheumatoid arthritis, psoriasis and
hyperlipidemia. IMO-3100 is currently being evaluated in a Phase 1
clinical program.

About Idera Pharmaceuticals, Inc.

Idera Pharmaceuticals is developing drug candidates that act by
modulating immune responses through specific Toll-like Receptors
(TLRs). TLRs, a family of immune system receptors and the immune
system's first line of defense, recognize pathogens and initiate an
immune response. Idera's DNA and RNA chemistry expertise has
generated a pipeline of compounds designed to interact with
specific TLRs for a broad range of diseases. Through its internal
pipeline and collaborative alliances, Idera has established a
portfolio of TLR-targeted therapeutic candidates for infectious
diseases, autoimmune and inflammatory diseases, cancer, and
respiratory diseases, and for use as vaccine adjuvants.

Idera Forward Looking Statements

This press release contains forward-looking statements
concerning Idera Pharmaceuticals, Inc. that involve a number of
risks and uncertainties. For this purpose, any statements contained
herein that are not statements of historical fact may be deemed to
be forward-looking statements. Without limiting the foregoing, the
words "believes," "anticipates," "plans," "expects," "estimates,"
"intends," "should," "could," "will," "may," and similar
expressions are intended to identify forward-looking statements.
There are a number of important factors that could cause Idera's
actual results to differ materially from those indicated by such
forward-looking statements; whether results obtained in preclinical
studies such as the studies referred to in this release will be
indicative of results obtained in future clinical trials; whether
products based on Idera's technology will advance into or through
the clinical trial process on a timely basis or at all and receive
approval from the United States Food and Drug Administration or
equivalent foreign regulatory agencies; whether, if the Company's
products receive approval, they will be successfully distributed
and marketed; whether the Company's collaborations will be
successful; whether the patents and patent applications owned or
licensed by the Company will protect the Company's technology and
prevent others from infringing it; whether Idera's cash resources
will be sufficient to fund the Company's operations; and such other
important factors as are set forth under the caption "Risk Factors"
in Idera's Quarterly Report on Form 10-Q for the three months ended
September 30, 2010, which important factors are incorporated herein
by reference. Idera disclaims any intention or obligation to update
any forward-looking statements.